[Lewy]

Hi all,

Recently, I am working on the fog collection simulation, in which I use denseParticleFoam to simulate the particle problem. And I set the wall interaction condition of my fog net as stick. The simulation run well. However, I have a question.

How does the openfoam determine the particles being stick to the wall?

As far as I am concerned, in Lagrangian frame, the position of particle doesn't have to be grid points. Maybe the judgement of stick is just close enough to the wall? I tried to find the relative source code but I failed.

I highly appreciate if anyone can give some help or ideas.

Regards

[joshwilliams]

Hi,


When integrating a particle's position in time, it may interact with a patch (see $FOAM_SRC/lagrangian/intermediate/parcels/Templates/KinematicParcel/KinematicParcel.C, Foam::KinematicParcel<ParcelType>::move).
The code to check if a particle interacts with a patch is all defined in $FOAM_SRC/lagrangian/basic/particle/


Essentially, it is a really core piece of the code to track if a point is on a face. Without trawling through the code myself, I am pretty sure that a collision is computed when the distance from a particle's center to the nearest face is less than one radius. In some other Lagrangian codes (LIGGGHTS with CFDEMCoupling), a collision is activated using a distance cutoff equal to the radius plus some small value (called "skin distance").


Best,
Josh

[Lewy]

Hi Josh,

Thanks a lot. That's very helpful.

[emadsiadati]

Hi,

And how about the cloud and parcel which include the particle?
just the particle leaves the cloud/parcel and sticks to the wall OR the whole cloud/parcel sticks to the wall when one of its particles sticks?